Architecture that wishes to be valid in the present and the future cannot simply resort to traditional forms and materials. It has to derive from formal developments based on a process of integral planning and organization that reflects current and future modes of human existence. It is not important how we have lived and worked hitherto, but how we shall live and work in the future.
In ecological terms, to build in a form appropriate to the present would require nothing less than erecting a structure that could be operated with regenerable forms of energy and from which there are no pollutant emissions. In integrating the development into its surroundings, the effects on the natural environment should be minimal; and the building would have to be recyclable.
New potential in the fields of production and assembly would be created in this way. Open layouts and circulation concepts would facilitate flexible forms of living and working. Flexible buildings, however, also imply complete flexibility in the service installations, waste disposal, energy and communications systems.
In our search for a way forward, we ourselves are constantly putting scientific experiment aside to test the validity of our premises in built experiments. These may concentrate on a small detail, or they may involve an entire building – as in the case of the house in Römerstrasse, which is a very personal manifestation of our architectural, artistic and social convictions.
Structures like the tower block in Stuttgart draw on the fruits of these experiments (architects: Murphy/Jahn; energy planning: Transsolar; structure and facade construction: Werner Sobek Ingenieure). The competition design for the Stuttgart tower proposed a building 220 m high and circular on plan with a diameter of 36 m. The lower zone would accommodate a hotel, and above this, there would be offices, dwellings, a restaurant and a viewing platform. A well-planned concept is necessary, both for the load-bearing structure and the energy technology, since the various functions stacked on top of each other usually have different layout requirements. This problem is typical of multipurpose buildings, and it applies in particular to the core, which in the present scheme possesses extremely thin reinforced concrete walls. These transmit only vertical loads. All horizontal loads are borne by an exoskeleton, which transmits a large part of the vertical loads as well. An exoskeleton of this kind can be regarded as a diagonalized tube, which is the most efficient system for transmitting the horizontal loads from high-rise buildings to the ground. Of all peripheral load-bearing systems, it is probably the one that requires the least volume and thus allows the greatest degree of transparency in the building skin.
With its storey-height glazing elements, the tower affords maximum views out to the attractive surroundings. The entire building is served by a decentralized air-supply system, which enables the cross-section of the core structure to be reduced and allows individual regulation of the indoor climate in each room. The facade can be opened wherever required, since the shingle-like suspended outer skin, consisting of storey-height glazed panels, screens the inner facade from precipitation and wind pressure.
The house in Römerstrasse in Stuttgart is situated on a sloping site and enjoys a magnificent view over the city. The development of the site was problematic on account of its shape and the narrow, steep line of access. The foundations of the new structure consist of a continuous floor slab with an integral downstand apron against frost. The load-bearing structure is in the form of a steel skeleton frame with Å-beams and 12-metre-high square hollow-section columns. The entire four-storey steel structure, which remains visible in the finished building, was assembled in four days. The floors consist of prefabricated laminated timber sheets with a synthetic covering. The sheets, roughly 3 x 4 m in size, are inserted between the floor beams and are only 6 cm thick.
The modular outer facade consists of storey-height units suspended in front of all four floors of the building in a three-layer construction (triple glazing filled with argon, with coated panes of glass and a coated synthetic layer in the middle; k = 0.4). This form of construction was used here for the first time. The central area of the roof is flat and is covered with a photovoltaic installation, which was also laid flat for formal reasons. There are no internal walls. The staircase, extending over four storeys, and the areas not covered by soffit elements form a continuous vertical space. The fully glazed facades create the impression that the outdoor realm flows through the building.
On the underside of the floor slabs are aluminium soffit elements. These house the lighting installation, acoustic absorbers and the pipe runs for the heating and cooling system in a building that otherwise possesses no thermal storage mass. Internal temperatures are controlled automatically according to values that can be set separately for each storey. An insulated thermal storage unit serves as a kind of “battery”: when internal temperatures rise above the required level, heat is absorbed by the storage unit and yielded again when it is needed. Since the grid of pipes covers about 40 per cent of the floor area, it is possible to work with very low flow temperatures, which ensures a high level of comfort. The central computer for the building allows the following functions to be programmed: indoor temperatures, the electrical operation of doors and windows, the regulation of internal and external lighting, the operation of the security system and much more. As a result, there are no switches, and no door or window handles. In compliance with recycling requirements, all service runs are laid along the inside of the facade in accessible ducts. The sanitary installations are housed in a two-storey block inserted within the building. Doors, toilet flushing, water temperatures, etc. are controlled via sensors, so that no physical contact is necessary.
One should not have the impression, however, that the building in Römerstrasse served primarily as a vehicle for exploring new technologies. On the contrary, the house reflects the search for a form of living appropriate to our times. The ideas developed for the Römerstrasse project can be applied in many other situations. In part, it is a personal reply to the question: “How should we go on?”
